Air conditioning apparatus

ABSTRACT

An air conditioning apparatus may include an outdoor unit through which a first fluid, such as refrigerant circulates, an indoor unit through which a second fluid, such as water circulates, a heat exchange device which is configured to connect the outdoor unit to the indoor unit and in which the first fluid and the second fluid are heat-exchanged with each other, a first inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at high-pressure flows, a second inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at low-pressure flows, and a third inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid in liquid form flows. The heat exchange device may include a bypass tube configured to bypass the second inner tube and a flow control valve provided in the bypass tube.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims the benefit of priority to Korean Patent Applications No. 10-2020-0010087, filed in Korea on Jan. 28, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

An air conditioning apparatus is disclosed herein.

2. Background

Air conditioning apparatuses are apparatuses that maintain air within a predetermined space in a most proper state according to a use and purpose thereof. In general, such an air conditioning apparatus includes a compressor, a condenser, an expansion device, and evaporator. Thus, the air conditioning apparatus has a refrigerant cycle in which compression, condensation, expansion, and evaporation processes of a refrigerant are performed to cool or heat a predetermined space.

The predetermined space may be variously provided according to a place in which the air conditioning apparatus is used. For example, the air conditioning apparatus may be used in a home or an office.

When the air conditioning apparatus performs a cooling operation, an outdoor heat exchanger provided in an outdoor unit may serve as a condenser, and an indoor heat exchanger provided in an indoor unit may serve as an evaporator. On the other hand, when the air conditioning apparatus performs a heating operation, the indoor heat exchanger may serve as the condenser, and the outdoor heat exchanger may serve as the evaporator.

In recent years, according to environmental regulations, there is a tendency to limit a type of refrigerant used in an air conditioning apparatus and to reduce an amount of used refrigerant. To reduce an amount of refrigerant to be used, a technique for performing cooling or heating by performing heat-exchange between a refrigerant and a predetermined fluid has been proposed. For example, the predetermined fluid may include water.

Japanese Patent Registration No. 5279919 (hereinafter “related art document”), which is entitled “Air Conditioning Apparatus”, and which is hereby incorporated by reference, discloses a system for performing cooling or heating through heat exchanger between a refrigerant and water. According to the related art document, the air conditioning apparatus includes an outdoor unit, a heat medium converter, and an indoor unit. The heat medium converter includes a heat exchanger, a fastening device disposed at an upstream side of the heat exchanger, and a refrigerant passage changing device disposed at a downstream side of the heat exchanger. The refrigerant passage changing device is connected to a refrigerant tube through which a refrigerant in a low-temperature state flows during a cooling operation.

However, according to such related art document, there is a risk that a plate-type heat exchanger may be frozen when an electronic expansion valve (EEV) of a non-operating plate heat exchanger leaks because a flow switching unit is always connected to the low-pressure gas tube. Also, one plate type heat exchanger acts as an evaporator, and the other plate heat exchanger acts as a condenser. A heating-based simultaneous operation in which a plurality of indoor units performs a heating operation is performed, an evaporation temperature of the plate type heat exchanger acing as the evaporator becomes below zero, and thus, there is a risk of freezing and breaking.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:

FIG. 1 is a schematic view of an air conditioning apparatus according to an embodiment;

FIG. 2 is a cycle diagram of the air conditioning apparatus according to an embodiment;

FIG. 3 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a heating operation of the air conditioning apparatus according to an embodiment;

FIG. 4 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a heating-based simultaneous operation of the air conditioning apparatus according to an embodiment;

FIG. 5 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a cooling operation of the air conditioning apparatus according to an embodiment;

FIG. 6 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a cooling-based simultaneous operation of the air conditioning apparatus according to an embodiment; and

FIG. 7 is a graph illustrating a set section of a pressure sensor value of an air conditioning apparatus according to an embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described with reference to the accompanying drawings. Exemplary embodiments will be described below with reference to the accompanying drawings. It is noted that the same or similar components in the drawings are designated by the same reference numerals as far as possible even if they are shown in different drawings. Further, in description of embodiments, when it is determined that detailed descriptions of well-known configurations or functions disturb understanding of the embodiments, the detailed descriptions will be omitted.

Also, in the description of the embodiments, the terms such as first, second, A, B, (a) and (b) may be used. Each of the terms is merely used to distinguish the corresponding component from other components, and does not delimit an essence, an order or a sequence of the corresponding component. It should be understood that when one component is “connected”, “coupled” or “joined” to another component, the former may be directly connected or jointed to the latter or may be “connected”, coupled” or “joined” to the latter with a third component interposed therebetween.

FIG. 1 is a schematic view of an air conditioning apparatus according to an embodiment. FIG. 2 is a cycle diagram illustrating the air conditioning apparatus according to an embodiment.

Referring to FIGS. 1 and 2, an air conditioning apparatus 1 according to an embodiment may be connected to an outdoor unit 200, an indoor unit 50, and a heat exchange device 100 connected to the outdoor unit 200 and the indoor unit 50. The outdoor unit 200 and the heat exchange device 100 may be fluidly connected by a first fluid. For example, the first fluid may include a refrigerant. The refrigerant may flow through a refrigerant-side passage of a heat exchanger, which is provided in the heat exchange device 100, and the outdoor unit 200.

The outdoor unit 200 may include a plurality of compressors 240 and 242 and oil separators 241 and 243, which may be disposed at outlet-sides of the plurality of compressors 240 and 242 to separate oil from the refrigerant discharged from the plurality of compressors 240 and 242.

The plurality of compressors 240 and 242 may include first compressor 240 and second compressor 242, which may be connected in parallel to each other. Also, the oil separators 241 and 243 may include first oil separator 241 disposed at an outlet-side of the first compressor 240 and second oil separator 243 disposed at an outlet-side of the second compressor 242.

The outdoor unit 200 may include a collection passage 245 that collects the oil from the oil separators 241 and 243 into the compressors 240 and 242. That is, the oil collection passage 245 may extend from the first oil separator 241 to the first compressor 240 and from the second oil separator 243 to the second compressor 242.

Flow switching portions 260 and 262 that guide the refrigerant discharged from the compressors 240 and 242 to the outdoor heat exchange device 200 or the indoor unit may be provided at outlet-sides of the oil separators 241 and 243. For example, the flow switching portions 260 and 262 may include first flow switching portion 260 and second flow switching portion 262. The flow switching portions 260 and 262 may be, for example, three-way valves.

When the air conditioning apparatus operates in a cooling mode, the refrigerant may be introduced from the flow switching portion 262 into the outdoor heat exchanger 210. On the other hand, when the air conditioning apparatus performs a heating operation, the refrigerant may be introduced from the flow switching portion 262 toward the indoor heat exchanger 300 of the indoor unit.

Also, the outdoor unit 200 may be provided with a gas-liquid separator 250 connected to inlet-sides of the plurality of compressors 240 and 242. The gas/liquid separator 250 may be configured to separate gaseous refrigerant from the refrigerant before the refrigerant is introduced into the compressors 240 and 242. The separated gaseous refrigerant may be introduced into the compressors 240 and 242.

When the air conditioning apparatus performs the cooling operation, the refrigerant passing through an outdoor heat exchange device 210 may be introduced into a third outdoor unit connection tube 27. The outdoor heat exchange device 210 may include a plurality of heat exchange portions (heat exchangers) 211 and 212 and an outdoor fan 218. The plurality of heat exchange portions 211 and 212 may include first heat exchange portion (heat exchanger) 211 and second heat exchange portion (heat exchanger) 212 which may be connected in parallel to each other.

Also, the outdoor heat exchange device 210 may include a variable passage 220 that guides a flow of the refrigerant from an outlet-side of the first heat exchange portion 212 to an inlet-side of the second heat exchange portion 212. The variable passage 220 may extend from a first outlet tube 230 which is an outlet-side tube of the first heat exchange portion 212 to an inlet tube 212 a which is an inlet-side tube of the second heat exchange portion 212.

A first valve 222 that selectively blocks a flow of the refrigerant flowing toward the variable passage 220 may be provided in the outdoor heat exchange device 210. The refrigerant passing through the first heat exchange portion 211 may be selectively introduced into the second heat exchange portion 212 according to whether the first valve 222 is turned on or off.

When the first valve 222 is turned on or opened, the refrigerant passing through the first heat exchange portion 211 flows into the inlet tube 212 a via the variable passage 220 and then is heat-exchanged in the second heat exchange portion 212. Also, the refrigerant passing through the second heat exchange portion 212 may be introduced into the third outdoor unit connection tube 27 through a second outlet tube 231. On the other hand, when the first valve 222 is turned off or closed, the refrigerant passing through the first heat exchange portion 211 may be introduced into the third outdoor unit connection tube 27 through the first outlet tube 230.

A second valve 232 that adjusts a flow of the refrigerant may be disposed in the first outlet tube 230, and a third valve 233 that adjusts a flow of the refrigerant may be disposed in the second outlet tube 231. The second valve 232 and the third valve 233 may be connected to each other in parallel.

When the second valve 232 is opened or increases in opening degree, an amount of refrigerant flowing through the first outlet tube 230 may increase. Also, when the third valve 233 is opened or increases in opening degree, an amount of refrigerant flowing through the second outlet tube 231 may increase.

Each of the second valve 232 and the third valve 233 may include an electronic expansion valve (EEV). The EEV may adjust a degree of opening thereof to allow a pressure of the refrigerant passing through the expansion valve to decrease. For example, when the expansion valve is fully opened, the refrigerant may pass through the expansion valve without decreasing, and when the degree of opening of the expansion valve decreases, the refrigerant may be decompressed. A degree of decompression of the refrigerant may increase as the degree of opening decreases.

The first outlet tube 230 and the second outlet tube 231 may be combined with each other and connected to the third outdoor unit connection tube 27.

The air conditioning apparatus 1 may further include outdoor unit connection tubes 21, 25, and 27 that connect the outdoor unit 200 to the heat exchange device 100. The outdoor unit connection tubes 21, 25, and 27 may include first outdoor unit connection tube 21 as a gas tube (a high-pressure gas tube) through which a high-pressure gas refrigerant may flow, second outdoor unit connection tube 25 as a gas tube (a low-pressure gas tube) through which a low-pressure gas refrigerant may flow, and third outdoor unit connection tube 27 as a liquid tube through which a liquid refrigerant may flow. That is, the outdoor unit 200 and the heat exchange device 100 may have a “three tube connection structure”, and the refrigerant may circulate through the outdoor unit 200 and the heat exchange device 100 by the three connection tubes 21, 25, and 27.

Also, the heat exchange device 100 may be provided with three inner tubes 11, 15, and 17 and be connected to the three outdoor unit connection tubes 21, 25, and 27, and the three inner tubes 11, 15, and 17 may be connected to the heat exchange device 100.

The heat exchange device 100 and the indoor unit 50 may be fluidly connected by a second fluid. For example, the second fluid may include water. The water may flow through a fluid passage of a heat exchanger, which is provided in the heat exchange device 100, and the outdoor unit 200.

The heat exchange device 100 may include a plurality of heat exchangers 140 and 141. Each of the heat exchangers 140 and 141 may include, for example, a plate heat exchanger.

The indoor unit 50 may include a plurality of indoor units 60 and 70. In this embodiment, the number of plurality of indoor units 60 and 70 is not limited. In FIG. 1, for example, two indoor units 60 and 70 are connected to the heat exchange device 100. The plurality of indoor units 60 and 70 may include first indoor unit 60 and second indoor unit 70.

The air conditioning apparatus 1 may further include tubes 30 and 35 that connect the heat exchange device 100 to the indoor unit 50. The tubes 30 and 35 may include first indoor unit connection tube 30 and second indoor unit connection tube 35, which connect the heat exchange device 100 to each of indoor units 60 and 70.

The water may circulate through the heat exchange device 100 and the indoor unit 50 via the indoor unit connection tubes 30 and 50. As the number of indoor units increases, the number of tubes connecting the heat exchange device 100 a to the indoor units may also increase.

According to the above-described configuration, the refrigerant circulating through the outdoor unit 200 and the heat exchange device 100 and the water circulating through the heat exchange device 100 and the indoor unit 50 are heat-exchanged with each other through the heat exchangers 140 and 141 provided in the heat exchange device 100. The water cooled or heated through heat exchange may be heat-exchanged with the indoor heat exchangers 61 and 71 to perform cooling or heating in the indoor space.

The plurality of heat exchangers 140 and 141 may be provided in the same number as the number of plurality of indoor units 60 and 70. Alternatively, two or more indoor units may be connected to one heat exchanger.

Hereinafter, the heat exchange device 100 will be described.

The heat exchange device 100 may include first heat exchanger 140 and second heat exchanger 141, which may be fluidly connected to indoor units 60 and 70, respectively. The first heat exchanger 140 and the second heat exchanger 141 may have a same structure.

Each of the heat exchangers 140 and 141 may include a plate heat exchanger, for example, and a first fluid passage and a second fluid passage may be alternately stacked. That is, the heat exchangers 140 and 141 may include first fluid passages 140 a and 141 a and second fluid passages 140 b and 141 b, respectively.

The first fluid passages 140 a and 141 a may be fluidly connected to the outdoor unit 200, and the refrigerant discharged from the outdoor unit 200 may be introduced into the first fluid passages 140 a and 141 a, and then the refrigerant passing through the first fluid passages 140 a and 141 a may be introduced into the outdoor unit 200. The second fluid passages 140 b and 141 b may be connected to each of the indoor units 60 and 70, and fluid, such as water discharged from each of the indoor units 60 and 70 may be introduced into the second fluid passages 140 b and 141 b, and then the fluid passing through the second fluid passages 140 b and 141 b may be introduced into each of the indoor units 60 and 70.

The heat exchange device 100 may include a first branch tube 101 and a second branch tube 102, which may be branched from the first inner tube 11. However, the number of branch tubes branched from the first inner tube 11 is not limited.

A high-pressure refrigerant may, for example, flow through the first branch tube 101 and the second branch tube 102. Therefore, the first branch tube 101 and the second branch tube 102 may be referred to as “high-pressure tubes”. The first branch tubes 101 and the second branch tubes 102 may be provided with first valves 103 and 104, respectively.

The heat exchange device 100 may include a third branch tube 105 and a fourth branch tube 106, which are branched from the second inner tube 15. However, the number of branch tubes branched from the second inner tube 15 is not limited. A low-pressure refrigerant may flow, for example, through the third branch tube 105 and the fourth branch tube 106. Therefore, the third branch tube 105 and the fourth branch tube 106 may be referred to as, for example, “low-pressure tubes”. The third branch tube 105 and the fourth branch tube 106 may be provided with second valves 107 and 108, respectively.

A flow control valve 161 may be further included in the second inner tube 15. For example, a valve 163 may be provided in the second inner tube 15, and the flow control valve 161 may be provided in parallel with the valve 163. The valve 163 may be a solenoid valve.

The flow control valve 161 may be provided in the bypass tube 162 branched from the second inner tube 15, and the valve 163 may be provided between the branch portion 162 a, which is an inlet-side and a combination portion 162 b which is an outlet-side of the branch portion 162 a. For example, the bypass tube 162 may be connected to the second inner tube 15 at the branch portion 162 a and the combination portion 162 b, and at least a portion of the refrigerant flowing through the second inner tube 15 may flow to the bypass tube 162.

An evaporation pressure of the second inner tube 15 may be controlled by adjusting an amount of refrigerant flowing through the second inner tube 15 through the flow control valve 161. Also, the second inner tube 15 may further include a pressure sensor 164 that measures a pressure of the second inner tube 15.

For example, the pressure sensor 164 may be provided at the outlet-side of the second inner tube 15. That is, the pressure sensor 164 may be provided between the branch tubes 105 and 106 of the second inner tube 15 and the flow control valve 161.

The heat exchange apparatus 100 may include a first common gas tube 111 to which the first branch tube 101 and the third branch tube 105 may be connected and a second common gas tube 112 to which the second branch tube 102 and the fourth branch tube may be connected.

The first common gas tube 111 may be connected to one or a first end of the first fluid passage 140 a of each of the heat exchangers 140 and 141. First and second tubes 121 and 122 may be connected to the other or a second end of the refrigerant passage of each of the heat exchangers 140 and 141.

The first tube 121 may be connected to the first heat exchanger 140, and the second tube 122 may be connected to the second heat exchanger 141. A first expansion valve 123 may be provided in the first refrigerant tube 121, and a second expansion valve 124 may be provided in the second refrigerant tube 122. The first refrigerant tube 121 and the second refrigerant tube 122 may be connected to the third inner tube 17.

Each of the expansion valves 123 and 124 may include, for example, an electronic expansion valve (EEV). The EEV may adjust a degree of opening thereof to allow a pressure of the refrigerant passing through the expansion valve to decrease. For example, when the expansion valve is fully opened, the refrigerant may pass through the expansion valve without decreasing, and when the degree of opening of the expansion valve decreases, the refrigerant may be decompressed. A degree of decompression of the refrigerant may increase as the degree of opening decreases.

The heat exchange device 100 may further include a fifth branch tube 113 that connects the third branch tube 105 to the first common gas tube 111. The fifth branch tube 113 allows the refrigerant to bypass the second valve 107 of the third branch tube 105. A first control valve 114 may be provided in the fifth branch tube 113.

The heat exchange device 100 may further include a sixth branch tube 115 that connects the fourth branch tube 106 to the second common gas tube 112. The sixth branch tube 115 allows the refrigerant to bypass the second valve 108 of the fourth branch tube 106. A second control valve 116 may be provided in the sixth control valve 116.

The first and second control valves 114 and 116 are valves capable of adjusting a flow rate of the refrigerant. That is, the control valve 114, 116 may be an electronic expansion valve capable of adjusting an opening degree.

The indoor unit connection tubes 30 and 35 may include heat exchanger inlet tubes 31 and 36 and heat exchanger outlet tubes 32 and 37. Each of the heat exchanger inlet tubes 31 and 36 may be provided with pumps 151 and 152, respectively.

Each of the heat exchanger inlet tubes 31 and 36 and each of the heat exchanger outlet tubes 32 and 37 may be connected to the indoor heat exchangers 61 and 71, respectively. The heat exchanger inlet tubes 31 and 36 may serve as indoor unit inlet tubes with respect to the indoor heat exchangers 61 and 71, and the heat exchanger outlet tubes 32 and 37 may serve as the indoor heat exchangers 61 and 71 with respect to the indoor heat exchangers 61 and 71.

FIG. 3 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in a heat exchange device during a heating operation of the air conditioning apparatus according to an embodiment. Referring to FIG. 3, when the air conditioning apparatus 1 performs the heating operation, high-pressure gas refrigerant compressed by compressors 240 and 242 of outdoor unit 200 may flow to first outdoor unit connection tube 21 and first inner tube 11 and then be branched into first branch tube 101 and second branch tube 102.

When the air conditioning apparatus 1 perform the heating operation, first valves 103 and 104 of first and second branch tubes 101 and 102 are opened, and second valves 107 and 108 of third and fourth branch tubes 105 and 106 are closed. Also, first and second bypass valves 114 and 116 may be closed.

The refrigerant branched into the first branch tube 101 flows along first common gas tube 111 and then flows into the first fluid passage 140 a of first heat exchanger 140. The refrigerant branched into the second branch tube 102 flows along second common gas tube 112 and then flows into the first fluid passage 141 a of second heat exchanger 141.

In this embodiment, when the air conditioning apparatus 1 performs the heating operation, each of the heat exchangers 140 and 141 may serve as a condenser. When the air conditioning apparatus 1 performs the heating operation, the first expansion valve 123 and the second expansion valve 124 are opened.

The refrigerant passing through the first fluid passages 140 a and 141 a of the heat exchangers 140 and 141 flows to third inner tube 17 after passing through each of expansion valves 123 and 124.

The refrigerant discharged into the third inner tube 17 may be introduced into the outdoor unit 200 and then be introduced into the compressors 240 and 242. For example, the refrigerant passing through third outdoor unit connection tube 27 may flow to the outdoor heat exchange device 210.

The refrigerant passing through the outdoor heat exchange device 210 to perform heat exchange may pass through second flow switching portion 262 to flow into the plurality of compressors 240 and 242. The high-pressure refrigerant compressed by the plurality of compressor 240 and 242 flows again to heat exchange device 100 through the first outdoor unit connection tube 21.

The second fluid, such as water flowing through the second fluid passages of each of the heat exchangers 140 and 141 may be heated by heat-exchange with the first fluid, such as refrigerant, and the heated fluid may be supplied to each of indoor heat exchangers 61 and 71 to perform the heating.

While each of the heat exchangers 140 and 141 performs the heating operation, valve 163 may be opened, and flow control valve 161 may be opened while maximizing an opening degree. That is, an amount of refrigerant flowing to the second inner tube 15 may be maximized.

FIG. 4 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a heating-based simultaneous operation of the air conditioning apparatus according to an embodiment.

The heating-based simultaneous operation of the air conditioning apparatus means a case in which the plurality of indoor units operates for heating. One of the heat exchangers 140 and 141 may perform heat exchange for heating, and the other may perform heat exchange for cooling.

For example, as described above, in the operation of the first heat exchanger 140, the first valve 103 of the first branch tube 101 is opened, the second valve of the third branch tube 105 is closed, and the first expansion valve 123 is opened so that the refrigerant flows as in the heating operation. However, the first valve 104 of the second branch tube 102 is closed, and the second valve 106 of the fourth branch tube 106 and the second expansion valve 124 are opened. Also, the bypass valves 114 and 116 are closed.

That is, the refrigerant branched from the third inner tube 17 and distributed to the second tube 122 may be reduced to low-pressure refrigerant while passing through the second expansion valve 124.

The decompressed refrigerant is evaporated through heat exchange with the second fluid along the first fluid passage of the second heat exchanger 141 and then flows to the second common gas tube 122. The refrigerant flowing to the second common gas tube 122 passes through the fourth branch tube 106 to flow into the second inner tube 15. The refrigerant flowing to the outdoor unit 200 may also flow in the same manner as when the air conditioning apparatus 1 performs the heating operation.

When the air conditioning apparatus 1 performs the heating-based simultaneous operation, an evaporation temperature of the heat exchanger that performs the heat exchange for the cooling may decrease below zero or less, and thus, there is a risk of freezing and breaking. Thus, it is possible to increase in evaporation pressure of the second inner tube 17 by applying a pressure loss through the flow control valve 161 provided in the second inner tube 17.

That is, when the air conditioner 1 operate the heating-based simultaneous operation, the valve 163 may be closed, and only the flow control valve 161 may be opened to adjust an amount of refrigerant flowing through the second inner tube 17. For example, the amount of refrigerant may be adjusted so that the evaporation temperature according to a pressure measured by the pressure sensor 164 exceeds 0° C.

FIG. 5 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a cooling operation of the air conditioning apparatus according to an embodiment. FIG. 6 is a cycle diagram illustrating flows of a first fluid, such as refrigerant and a second fluid, such as water in the heat exchange device during a cooling-based simultaneous operation of the air conditioning apparatus according to an embodiment.

Referring to FIG. 5, when the air conditioning apparatus 1 performs the cooling operation, high-pressure liquid refrigerant condensed in the outdoor heat exchanger 210 of the outdoor unit 200 may flow through the third outdoor unit connection tube 27 and the third inner tube 17 and then be distributed into the first tube 121 and the second tube 122.

As the expansion valves 123 and 124 provided in the first and second tubes 121 and 122 are opened to a predetermined degree, the refrigerant may be decompressed into the low-pressure refrigerant while passing through the expansion valves 123 and 124.

The decompressed refrigerant may be heat-exchanged with the second fluid, and thus, be evaporated while flowing along the first fluid passages 140 a and 141 a of the heat exchangers 140 and 141. That is, when the air conditioning apparatus 1 performs the cooling operation, each of the heat exchangers 140 and 141 may serve as an evaporator.

While the air conditioning apparatus 1 performs the cooling operation, the first valves 103 and 104 of the first and second branch tubes 101 and 102 are closed, and the second valves 107 and 108 of the third and fourth branch tubes 105 and 106 are opened. Also, the bypass valves 114 and 116 may be closed. Therefore, the refrigerant passing through the first fluid passages 140 a and 141 a of the heat exchangers 140 and 141 flows to each of the common gas tubes 111 and 112. The refrigerant flowing to each of the common gas tubes 111 and 112 flows into the second inner tube 15 after flowing through the third and fourth branch tubes 105 and 106.

The refrigerant discharged into the second inner tube 15 may be introduced into the outdoor unit 200 and be suctioned into the compressor 240. The high-pressure refrigerant compressed by the compressors 240 and 242 may be condensed in the outdoor heat exchanger 210, and the condensed liquid refrigerant may again flow along the third outdoor unit connection tube 27.

As the flow of the second fluid is the same as that described in FIG. 3, detailed description thereof has been omitted.

FIG. 6 illustrates a flow of a first fluid, such as refrigerant and a second fluid, such as water when the air conditioning apparatus 1 performs the cooling-based simultaneous operation, that is, when the plurality of indoor units performs the cooling operation. That is, one of the heat exchangers 140 and 141 may perform heat exchange for heating, and the other may perform heat exchange for cooling. The outdoor unit 200 may be the same as that of the cooling operation as described in FIG. 5.

While each of the heat exchangers 140 and 141 performs the heating operation, the valve 163 may be opened, and the flow control valve 161 may be opened while maximizing an opening degree. That is, an amount of refrigerant flowing to the second inner tube 15 may be maximized.

FIG. 7 is a graph illustrating a set section of a pressure sensor value of an air conditioning apparatus according to an embodiment. Referring to FIG. 7, it can be seen that the opening degree of the flow control valve 161 is controlled by the low-pressure gas tube, that is, the pressure or temperature of the second inner tube 25.

The flow control valve 161 may adjust the amount of the refrigerant so that the pressure measured by the pressure sensor 164 decreases to be belong to a predetermined pressure section. The predetermined pressure section may be a section ranging from a first pressure P1 to a second pressure P2.

For example, when the pressure measured by the pressure sensor 164 is less than the first pressure P1, the opening degree of the flow control valve 161 may be decreased, and the pressure measured by the pressure sensor 164 exceeds the second pressure P2, the opening degree of the flow control valve may be increased. The term “constant pressure section” refers to a section in which a temperature of refrigerant according to the pressure exceeds 0° C.

The first pressure P1 may refer to a pressure at which the evaporation temperature of the second inner tube 25 according to the first pressure P1 exceeds 0° C. That is, an evaporation temperature T1 of the second inner tube 25 according to the first pressure P1 may be greater than 0° C.

Also, in order that the heat exchange device 100 operates, the second inner tube 25 has to function as the low-pressure gas tube, and thus, the second inner tube 25 may be maintained to be less than a certain pressure. That is, the pressure measured by the pressure sensor 164 may be equal to or less than the second pressure P2. For example, the first pressure P1 may be about 740 kPaG, and the second pressure P2 may be about 800 kPaG.

According to embodiments disclosed herein, as the evaporation pressure of the heat exchanger provided in the outdoor unit decreases due to the low-temperature outdoor environment during the heating-based simultaneous operation, the evaporation pressure of the heat exchanger provided in the heat exchange device may also decrease to prevent the heat exchanger from being frozen. In addition, the flow rate of the low-pressure gas tube may be adjusted to control the evaporation temperature of the low-pressure gas tube so as to be maintained at 0° C. or higher, thereby preventing the heat exchanger provided in the heat exchange device from being frozen. In addition, as the flow rate of the compressor increases without being affected by the evaporation pressure of the heat exchanger provided in the outdoor unit, it may be possible to prevent heating efficiency from being deteriorated.

Embodiments disclosed herein provide an air conditioning apparatus in which a fluid, such as water is frozen in a passage of a heat exchanger during a heating-based simultaneous operation. Embodiments disclosed herein provide an air conditioning apparatus in which an evaporation temperature of a heat exchanger is 0° C. or higher regardless of an outdoor temperature. Embodiments disclosed herein provide an air conditioning apparatus in which a flow rate in a compressor increases regardless of an evaporation temperature of a heat exchanger provided in an outdoor unit.

In an air conditioning apparatus according to embodiments disclosed herein, a pressure of a low-pressure gas tube may be adjusted through a flow control valve to prevent a heat exchanger, which performs heat exchange for a cooling operation of an indoor unit, from being frozen during a heating-based simultaneous operation.

In one embodiment according to embodiments disclosed herein, an air conditioning apparatus may include an outdoor unit through which a first fluid, such as refrigerant circulates; an indoor unit through which a second fluid, such as water circulates; a heat exchange device which is configured to connect the outdoor unit to the indoor unit and in which the first fluid and the second fluid are heat-exchanged with each other; a first inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at high-pressure flows; a second inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at low-pressure flows; and a third inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid in liquid form flows. The heat exchange device may include a bypass tube configured to bypass the second inner tube, and a flow control valve provided in the bypass tube.

The heat exchange device may include a branch portion to which one or a first end of which the bypass tube is connected to the second inner tube, and a combination portion at the other or a second end of which the bypass tube is connected to the second inner tube. The heat exchange device may further include a valve provided between the branch portion and the combination portion.

A pressure sensor may be provided in the second inner tube, and the pressure sensor may be configured to measure a pressure of the first fluid before the first fluid is branched at the branch portion. When a heating-based simultaneous operation is performed, the valve may be closed.

The flow control valve may adjust an opening degree so that a pressure measured by the pressure sensor belongs to a pressure section ranging from a first pressure (P1) to a second pressure (P2). When the pressure measured by the pressure sensor is less than the first pressure (P1), the opening degree of the flow control valve may decrease, and when the pressure measured by the pressure sensor exceeds the second pressure (P2), the opening degree of the flow control valve may increase.

An evaporation temperature of the second inner tube depending on the first pressure (P1) may exceed 0° C. When a heating operation is performed, the flow control valve may be opened to a maximum opening degree.

The heat exchange device may include a first heat exchanger and a second heat exchanger; a first branch tube and a second branch tube, which are branched from the first inner tube; and third branch tube and a fourth branch tube, which are branched from the second inner tube. The air conditioning apparatus may further include a first valve provided in each of the first branch tube and the second branch tube, and a second tube provided in each of the third branch tube and the fourth branch tube.

The air conditioning apparatus may further include a first refrigerant tube and a second refrigerant tube, which are branched from the third inner tube, a first expansion valve provided in the first refrigerant tube; and a second expansion valve provided in the second refrigerant tube. The air conditioning apparatus may further include a first common gas tube to which the first branch tube and the third branch tube are connected; a fifth branch tube configured to connect the second branch tube to a second common gas tube; a first bypass valve provided in the fifth branch tube; the second common gas tube to which a third branch tube and a fourth branch tube are connected; a sixth branch tube configured to connect the fourth branch tube to the second common gas tube; and a second bypass valve provided in the sixth branch tube.

Each of the heat exchangers may include a first fluid passage through which the first fluid flows, and a second fluid passage through which the second fluid to be heat-exchanged with the first fluid within the first fluid passage flows. The second fluid flowing through the second fluid passage may flow to the indoor unit.

It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Embodiments of the disclosure are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

What is claimed is:
 1. An air conditioning apparatus, comprising: an outdoor unit through which a first fluid circulates; an indoor unit through which a second fluid circulates; a heat exchange device which is configured to connect the outdoor unit to the indoor unit and in which the first fluid and the second fluid are heat-exchanged with each other; a first inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at high pressure flows; a second inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at low pressure flows; and a third inner tube which is configured to connect the outdoor unit to the heat exchange device and through which first fluid in liquid form flows, wherein the heat exchange device comprises: a bypass tube configured to bypass the second inner tube; and a flow control valve provided in the bypass tube.
 2. The air conditioning apparatus according to claim 1, wherein the heat exchange device comprises: a branch portion at a first end of which the bypass tube is connected to the second inner tube; and a combination portion at a second end of which the bypass tube is connected to the second inner tube.
 3. The air conditioning apparatus according to claim 2, wherein the heat exchange device further comprises a valve provided between the branch portion and the combination portion.
 4. The air conditioning apparatus according to claim 3, wherein a pressure sensor is provided in the second inner tube.
 5. The air conditioning apparatus according to claim 4, wherein the pressure sensor is configured to measure a pressure of the first fluid before the first fluid is branched at the branch portion.
 6. The air conditioning apparatus according to claim 4, wherein, when a heating-based simultaneous operation is performed, the valve is closed.
 7. The air conditioning apparatus according to claim 6, wherein the flow control valve adjusts an opening degree so that a pressure measured by the pressure sensor belongs to a pressure section ranging from a first pressure (P1) to a second pressure (P2).
 8. The air conditioning apparatus according to claim 7, wherein, when the pressure measured by the pressure sensor is less than the first pressure (P1), the opening degree of the flow control valve is decreased, and when the pressure measured by the pressure sensor exceeds the second pressure (P2), the opening degree of the flow control valve is increased.
 9. The air conditioning apparatus according to claim 8, wherein an evaporation temperature of the second inner tube depending on the first pressure (P1) exceeds 0° C.
 10. The air conditioning apparatus according to claim 3, wherein, when a heating operation is performed, the flow control valve is opened to a maximum opening degree.
 11. The air conditioning apparatus according to claim 1, wherein the heat exchange device comprises: a first heat exchanger and a second heat exchanger; a first branch tube and a second branch tube, which are branched from the first inner tube; and a third branch tube and a fourth branch tube, which are branched from the second inner tube.
 12. The air conditioning apparatus according to claim 11, further comprising: a first valve provided in each of the first branch tube and the second branch tube; and a second tube provided in each of the third branch tube and the fourth branch tube.
 13. The air conditioning apparatus according to claim 1, further comprising: a first tube and a second tube, which are branched from the third inner tube; a first expansion valve provided in the first tube; and a second expansion valve provided in the second tube.
 14. The air conditioning apparatus according to claim 1, further comprising: a first common tube to which the first branch tube and the third branch tube are connected; a fifth branch tube configured to connect the second branch tube to a second common tube; a first bypass valve provided in the fifth branch tube; the second common tube to which a third branch tube and a fourth branch tube are connected; a sixth branch tube configured to connect the fourth branch tube to the second common tube; and a second bypass valve provided in the sixth branch tube.
 15. The air conditioning apparatus according to claim 1, wherein each of the heat exchangers comprises: a first fluid passage through which the first fluid flows; and a second fluid passage through which the second fluid to be heat-exchanged with the first fluid within the first fluid passage flows, wherein the second fluid flowing through the second fluid passage flows to the indoor unit.
 16. An air conditioning apparatus, comprising: an outdoor unit through which a first fluid circulates; a plurality of indoor units through which a second fluid circulates; a heat exchange device which is configured to connect the outdoor unit to the plurality of indoor units and in which the first fluid and the second fluid are heat-exchanged with each other; a first inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at high pressure flows; a second inner tube which is configured to connect the outdoor unit to the heat exchange device and through which the first fluid at low pressure flows; and a third inner tube which is configured to connect the outdoor unit to the heat exchange device and through which first fluid in liquid form flows, wherein the heat exchange device comprises: a bypass tube configured to bypass the second inner tube; and a flow control valve provided in the bypass tube, wherein the heat exchange device comprises: a branch portion at a first end of which the bypass tube is connected to the second inner tube; and a combination portion at a second end of which the bypass tube is connected to the second inner tube, wherein the heat exchange device further comprises a valve provided between the branch portion and the combination portion.
 17. The air conditioning apparatus according to claim 16, wherein a pressure sensor is provided in the second inner tube.
 18. The air conditioning apparatus according to claim 17, wherein the pressure sensor is configured to measure a pressure of the first fluid before the first fluid is branched at the branch portion.
 19. The air conditioning apparatus according to claim 18, wherein the flow control valve adjusts an opening degree so that a pressure measured by the pressure sensor belongs to a pressure section ranging from a first pressure (P1) to a second pressure (P2).
 20. The air conditioning apparatus according to claim 19, wherein when the pressure measured by the pressure sensor is less than the first pressure (P1), the opening degree of the flow control valve is decreased, and when the pressure measured by the pressure sensor exceeds the second pressure (P2), the opening degree of the flow control valve is increased. 